Agricultural machines towed by a tractor across a field for picking up windrowed crop material to form a cylindrical bale are commonly referred to as round balers. These machines have either a fixed or an expandable bale forming chamber disposed between opposing vertical sidewalls. The chamber is usually defined by a floor and transverse confining means comprising a continuous flexible apron and/or a plurality of transverse rolls. Frequently the apron includes an array of side-by-side belts trained around a series of rollers that extend between the sidewalls, and the floor consists of either a large roller or a continuous conveyor belt.
During field operation, crop material such as hay is picked up from the ground and fed into the chamber. The volume of crop material increases continuously in the chamber until a compact cylindrical package is formed. The package is wrapped while still in the chamber and then ejected onto the ground as a completed bale.
Round balers of the general type mentioned above comprising a chamber defined at least partially by a plurality of side-by-side, longitudinally extending belts supported on a plurality of transverse rollers have encountered problems of varying degree caused by trash, such as stray crop material and other debris, that finds its way into the mounting bearings for the transverse rollers. When the crop material being baled is damp, and particularly if it is a short cut of grass crop, fine random debris from the crop material being formed into a cylindrical package in the chamber is also a cause for concern. Field experience has shown that standard bearing seals when continuously exposed to unwanted trash are not sufficient to prevent debris from working its way into the bearing cavity. Eventually, if permitted to go uncorrected, serious wear problems may occur culminating in bearing failure.
In one known round baler where these problems could occur the configuration includes an apron having an expandable inner course of side-by-side belts which cooperates with a sledge assembly to define a bale chamber which expands between a bale starting position and a full bale position. The sledge assembly includes a plurality of driven rollers and an idler roller in engagement with the apron belts to maintain the apron in close proximity to one of the driven rollers during movement of the sledge assembly between the bale starting and full bale positions. The idler roller is commonly referred to as a follower roll. This type of baler is disclosed in U.S. Pat. No. 4,870,812, issued Oct. 3, 1989 in the name of Richard E. Jennings, et al.
In round balers of this type, as well as all other types, durability and reliability are very important design concerns. For example, as mentioned above, serious problems arise under conditions where trash is permitted to build up in the roll bearing area resulting in down time and costly repair if not rectified on a timely basis. Of specific concern are the bearings for rolls located in particularly critical areas insofar as crop residue and debris being trapped are concerned. An example of such an area is the follower roll on the sledge assembly of the baler disclosed in U.S. Pat. No. 4,870,812, mentioned above.
Various prior art round balers have been provided with mechanisms that address the problem of unwanted trash accumulation. For example, adjacent belt paths have been transversely staggered at a particular point along their path to provide egress between adjacent belts for trapped debris as shown in U.S. Pat. No. 4,399,746, issued Aug. 23, 1983 in the name of Jean Viaud. Twisted belts have also been employed on round balers in another attempt to solve the same problem of trapped debris, which approach is disclosed in U.S. Pat. No. 4,707,974, issued Nov. 24, 1987.
In other prior art efforts to remove unwanted trash from round balers, active discharge mechanisms have been utilized, such as the transverse belt arrangement shown in U.S. Pat. No. 5,080,009, issued Jan. 14, 1992 in the name of David P. Fritz, et al, and rotating elements projecting between the belts as shown in U.S. Pat. No. 5,090,760, issued Mar. 24, 1992 in the name of Howard J. Ratzlaff, et al. In still another arrangement a passive discharge arrangement has been used wherein a discharge gate is provided in the rear section of the baler sidewall as disclosed in U.S. Pat. No. 4,444,098, issued Apr. 24, 1984 in the name of Gust S. Soteropulos.
The problem of trash accumulation in critical areas of and round balers is troublesome in varying degree throughout all baling conditions from the extremes of high moisture hay to low moisture hay or straw. When trash accumulates and eventually becomes entrapped or wraps in the roller bearing areas potentially significant problems could arise having a serious effect on baler performance.